This is the only AM3 SLI board on the market that I know of. Your DDR3 support and all, if you wait a little longer there may be more. It has been out less than a week or so. Doubt you'll find one second hand.

Either one would be a great choice it looks like, and for CPU, it's really debatable. Some say just go with the PII 955 and save yourself the money, and others say the 965. I personally would go with the 965 if budget allows, they seem to all hit 4ghz on air and 4ghz on stock voltage. The 955 is a great choice though too, so really up to you.